Cell Structure and Function

Chapter 3

Size Comparison

Domain II: Cellular Basis of Life

*Explain the cellular basis of life

*Homeostasis

*Transport cellular material through cell membrane

*Stem Cells

What is a Stem Cell?• What have you heard about stem cells?• Where do you think stem cells come

from?• What are stem cells for?• What is a cell?• What do you think is the benefit of

stem cells?

Cute Stem Cell

Animation

Name the 3 parts of the Cell Theory?

• 1) Cell is the basic unit of life

• 2) All organisms are composed of cells

• 3) All cells come from pre-existing cells

Who were the initial cell Scientists? Pg.71

• Robert Hooke 1665. First to see a cell. Named it after Monk Cells. (Cork)

• Anton van Leeuwenhoek 1673. 1st to see microscopic organisms.

What characteristics are needed to consider something alive?

• 1) Require food for energy

• 2) Use energy to maintain homeostasis

• 3) Respond to stimuli

• 4) Grow and develop

• 5) Reproduce similar offspring

• 6) Ability to pass genetic information

• 7) Made of cells

What is the difference between a multicellular and unicellular organism?

• Unicellular – exist as a single independent cell. Example: amoeba

• Multicellular- organisms that exist as specialized groups of cells.

• Order of cellular specialization: cells, tissues, organs, organ systems, organism

Which of the following is a correct statement regarding tissues?

• A) Tissues hold organs together• B) Tissues form plasma membranes• C) Tissues are composed of organs

with several functions• D) Tissues are composed of cells with

similar functions

• Answer: D

What is the difference between a prokaryote and a eukaryote?

• Prokaryote-No membrane bound organelles. Only bacteria are considered prokaryotes. pg.72

• Eukaryote- Contains membrane bound organelles, including a true nucleus.

Cell Comparisons

Which of the following is an example of a prokaryotic cell?

• A)An animal cell• B) A bacterial cell• C) A fungal cell• D) A plant cell

• Answer : b, both archae and Eubacteria are prokaryotes

What do all cells have in common?• Have a plasma membrane- semi-

permeable structure surrounding the cell

• Cytoplasm- jelly-like substance where cells chemical reactions occur as well as where organelles are found.

Fluid-Mosaic Model

How are cells different?

• Size: Cells must be small for diffusion. The closer the surface Area/Volume ration the more diffusion. Shape: Fig 4-2. Long, Flat, Branching, etc.

• Type of organelles and the number of each kind. (Red blood cells have no nucleus, Animal cells have no cell wall.)

• Different types of cells have different needs therefore different structures.

StemCell

Differentiation

What is a stem cell?

What is an Organelle?

• Part of a cell that performs a job. Like an organ does a job for the body organelles do the same for a cell.

United streaming video clip

Cell Movie: Amoebas &Animal Cells

Which organelles are found in plant cells but not in animal

cells?

• Plastids such as Chloroplast- capture solar energy for photosynthesis

• Cell Wall- Adds structure and support to the cell

• Plants also have much larger vacuoles for storing water then animal cells. Classzone

Animal Vs.Plant

Define the following organelles: Golgi bodies, Mitochondria, Nucleus,

Ribosome, and Vacuoles.

• Golgi bodies- package and distribute lipids and proteins

• Mitochondria- powerhouse of the cell, transforms energy

Definitions continued…

• Nucleus- contains DNA which controls cellular activities

• Ribosomes- produce proteins, found on the rough ER

• Vacuoles- store substances such as water.

Define the following organelles:Smooth Endoplasmic Reticulum (ER), Rough ER,

• Smooth Endoplasmic Reticulum (ER): Make Fats such as steroids.

• Rough ER: Contain Ribosomes. Package and ship proteins made on Ribosomes.

Organelles Continued

• Lysosome: Contain Digestive enzymes. Think SOS…

• Nucleolus: Ribosomes and other RNA are synthesized.

Great Lysosome

Short Movie

Define the following organelles

• Flagella: Whip like structure made of microtubules. Few in number and long.

• Cilia: numerous short hair-like structures. Also made of Microtublules. Flagella and Cillia

Video ClipVery Good!

In the animal cell, in which cell part does cellular respiration occur?

• A)

• B)

• C)

• D)• Answer: A Mitochondria

Organelle Review

Link

Organelle Self-Quiz

Review: Which of the following is a characteristic of all living

things?• A) Cellular Structure• B) Nervous System• C) Chlorophyll• D) Hemoglobin

• Answer: A

Review: What is homeostasis?

• Maintenance of internal equilibrium

• Example: Body to returning to normal temperature (98.7) after a fever.

Which of the following statements best demonstrates homeostasis?

• A) The intestine has a large surface area.

• B) Humans tend to have 5 fingers on each hand.

• C) Humans sweat when they get hot• D) Cells have maximum attainable

size.• Answer:C

Back to Stem Cells!

• How are stem cell made?

• Why do you think stem cells exist?

• Do differentiated cells have different organells?

MakingStemCells

Ch 3.4 & 3.5: Homeostasis and Transport

• How do substance enter and exit a cell?

• What is the difference between active and passive transport?

• How does the chemical make-up of the plasma membrane affect what can enter and exit the cell?

MembraneTransport

The plasma membrane only allows certain things to enter and exit the cell. What is this

called?• Selectively permeable membrane or

selectively permeable

What is passive transport? Name and describe the 3 types.

• Passive Transport- movement of substance of substances across the plasma membrane without the use of energy.

Passive Transport

The Three TypesDiffusion: movement of substances across

the plasma membrane from high to low concentration

Osmosis: diffusion of water across the plasma membrane from high to low concentration

Facilitated Diffusion: carrier molecules transport larger substances across the membrane from high to low.

What is active transport? Describe the two major types.

• Active Transport: uses energy and carrier molecules to move substances across the plasma membrane from low to high concentrations (against the concentration gradient)

Active Transport

The two types of Active Transport

•Endocytosis: process by which large particles are brought into the cell

•Exocytosis: process by which large particles leave the cell

Endo/Exocytosis

Substances that are too large to be moved across the plasma membrane can be engulfed through the process of …

• A) Diffusion

• B) Endocytosis

• C) Exocytosis

• D) Osmosis• Answer: B

• Endo= inside, Exo= Outside, cyto=cell, osis= process or action

There are 3 types of solutions a cell can be in.

• 1) Hypotonic

• 2) Hypertonic

• 3) IsotonicHypo/Hyper/

IsoScroll Down

Hypo/Hyper/Iso Solutions

Red blood cell

Describe a cell in an isotonic solution.

• Iso= the same. The concentration of the solution is the same inside and outside the cell.

• The cell stays the same size.

• There is no net movement across the plasma membrane (things enter and leave the cell at the same rate)

Describe a cell in an hypertonic solution.

• Hyper= above. The concentration of the solution is higher outside the cell than inside.

• The cell shrivels in size.

• Water leaves the cell at a faster rate then it enters.

Describe a cell in an hypotonic solution.

• Hypo= below. The concentration of solutions is lower outside the cell then inside.

• The cell swells or pops in size. hyPO=POP

• Water enters the cell at a faster rate than it leaves

A student is making a model to demonstrate how cells respond to solutions with varying

concentrations of salt and water. She soaked a kidney bean in distilled water until it started to swell. In what kind of solution should she put

the swollen bean to cause it to shrivel?

• A) Acidic

• B) Basic

• C) Hypertonic

• D) Hypotonic• Answer: C